The present invention relates generally to semiconductor devices and more particularly, to a structure and method of forming a photovoltaic cell using a surface treatment to improve device performance.
Electricity generated from photovoltaic cells may not be in grid parity with other electric generating units in many parts of the United States. To achieve widespread grid parity, substantial reductions in cost and improvements in performance may need to be achieved. Cost reductions may be achieved through innovative photovoltaic cell fabrication techniques. Performance improvements may be achieved by improving efficiency, which may be accomplished by improving short circuit current, fill factor, and open circuit voltage.
In a photovoltaic cell, surface level pinning may exist at a junction between layers due to a high surface state density. Surface level pinning may limit open circuit voltage and reduce fill factor in a photovoltaic cell. Overcoming strong surface Fermi level pinning may increase open circuit voltage and fill factor in a photovoltaic device, thus increasing device efficiency. However, overcoming strong surface Fermi level pinning may be challenging.